Preheat oven to 350°F for perfect baking.
Grease the pan with melted butter evenly.
Cream butter and sugar until light and fluffy.
Beat eggs one at a time into the mixture.
Add vanilla extract and continue mixing gently.
In another bowl, whisk flour, baking powder, salt.
Slowly add dry mix into butter mixture.
Alternate with buttermilk until batter is smooth.
Pour batter into the greased baking pan.
Smooth the top with a spatula evenly.
Bake for 45 minutes until golden brown.
Brush top with melted butter and sprinkle sugar.
Let cake cool on rack before serving.